C-4
C-4 or Composition C-4 is a common variety of the plastic explosive family known as Composition C. The British version of the explosive is known as PE-4. C-4 is composed of explosives, plastic binder, plasticizer to make it malleable, and usually a marker or odorizing taggant chemical. C-4 has a texture similar to modeling clay and can be moulded into any desired shape. C-4 is stable and an explosion can only be initiated by the combination of extreme heat and shock wave from a detonator. Characteristics and Uses Composition The Composition C-4 used by the United States Armed Forces contains 91% RDX ("Research Department Explosive", an explosive nitroamine), 5.3% dioctyl sebacate (DOS) or dioctyl adipate (DOA) as the plasticizer (to increase the plasticity of the explosive), 2.1% polyisobutylene (PIB, a synthetic rubber) as the binder, and 1.6% of a mineral oil often called "process oil". Instead of "process oil", low-viscosity motor oil is used in the manufacture of C-4 for civilian use. Technical data according to Department of the Army follow. Manufacture C-4 is manufactured by combining the above ingredients with binder dissolved in a solvent. Once the ingredients have been mixed, the solvent is extracted through drying and filtering. The final material is a solid with a dirty white to light brown color, a putty-like texture similar to modeling clay, and a distinct smell of motor oil. Depending on its intended usage and on the manufacturer, there are differences in the composition of C-4. For example, a 1990 U.S. Army technical manual stipulated that Class IV composition C-4 consists of 89.9±1% RDX, 10±1% polyisobutylene, and 0.2±0.02% dye that is itself made up of 90% lead chromate and 10% lamp black. RDX classes A, B, E, and H are all suitable for use in C-4. Classes are measured by granulation. The manufacturing process for Composition C-4 specifies that wet RDX and plastic binder are added in a stainless steel mixing kettle. This is called the aqueous slurry-coating process.The kettle is tumbled to obtain a homogeneous mixture. This mixture is wet and must be dried after transfer to drying trays. Drying with forced air for 16 hours at 50 °C to 60 °C is recommended to eliminate excess moisture. :198 Detonation A detonation within a blast resistant trash receptacle using a large C-4 explosive charge. C-4 is very stable and insensitive to most physical shocks. C-4 cannot be detonated by a gunshot or by dropping it onto a hard surface. It does not explode when set on fire or exposed to microwave radiation. Detonation can only be initiated by a combination of extreme heat and a shockwave, such as when a detonator inserted into it is fired. When detonated, C-4 rapidly decomposes to release nitrogen and carbon oxides as well as other gasses. The gasses expand at an explosive velocity of 8,092 m/s (26,550 ft/s). After the initial explosion, gasses rush back toward the center of the explosion causing a second, inward wave of energy. A major advantage of C-4 is that it can easily be moulded into any desired shape to change the direction of the resulting explosion. Form Military grade C-4 is commonly packaged as the M112 demolition block. The demolition charge M112 is a rectangular block of Composition C-4 approximately 2 inches by 1.5 inches and 11 inches long, weighing 1.25 Lbs. The M112 is wrapped in a sometimes olive color Mylar-film container with a pressure-sensitive adhesive tape on one surface. The M112 demolition blocks of C-4 are commonly manufactured into the M183 "demolition charge assembly", which consists of 16 M112 block demolition charges and four priming assemblies packaged inside military Carrying Case M85. The M183 is used to breach obstacles or demolish large structures where larger satchel charges are required. Each Priming assembly includes a five-, or twenty-foot length of detonating cord assembled with detonating cord clips and capped at each end with a booster. When the charge is detonated, the explosive is converted into compressed gas. The gas exerts pressure in the form of a shock wave, which demolishes the target by cutting, breaching, or cratering. Other forms include the mine-clearing line charge (MICLIC) and M18A1 Claymore Mine. Category:Explosives Category:Plastic explosives